Pumping system

ABSTRACT

A pumping system comprising a commutator motor and a directly driven pump, the motor being surrounded over substantially its entire periphery by a cooling jacket loaded with the liquid to be pumped and at least in part formed of the double wall of the motor housing, the motor further being completely sealed from the cooling jacket and being provided at its center with a ventilator mounted on the shaft for the purpose of air circulation. The improvements include mounting the commutator in the vicinity of the pump side of the motor, said pump side also being cooled, and mounting the ventilator at the opposite end of the shaft to allow for particularly effective and compact cooling of the motor.

O United States Patent 1191 3,897,178

Palloch July 29, 1975 PUMPING SYSTEM 2,468,187 4/1949 Ericson 417/369 3,11 4 [75] Inventor: Herbert Palloch, Schwetzingen, 5 839 12/1963 Pollak at al 17/369 Baden, Germany FOREIGN PATENTS OR APPLICATIONS [73] Assigneez Frank & Kirchner, 1,703,433 5/1968 Germany 417/368 Schwetzingen/Baden, Germany Primary Examiner-C. J. Husar [22] Flled? W- 101 1973 Attorney, Agent, or Firm-Browdy and Neimark [21] Appl. No.: 396,103

[57] ABSTRACT 30 Foreign Application Priority Data A p gi gm comprising commutator motor an a lrecty riven pump, t e motor emg sur- Sept. 9, 1972 Germany 2244275 rounded over Substantially its entire p p y y a cooling jacket loaded with the liquid to be pumped [52] 417/368 417/366 6 and at least in part formed of the double wall of the [51] Int Cl 2 F04B 39/06 motor housing, the motor further being completely [58] Fie'ld 368 369 sealed from the cooling jacket and being provided at i 8 its center with a ventilator mounted on the shaft for the purpose of air circulation. The improvements in- [56] References Cited clude mounting the commutator in the vicinity of the pump side of the motor, said pump side also being UNITED STATES PATENTS cooled, and mounting the ventilator at the opposite 2,321,126 6/1943 Brewer 117/32; end of the haft to allow for particularly effective and 2,394,860 2/1946 Korte 17 3 t fth t 2,410,973 11/1946 Hoover 417/367 compac Coo mg 0 6 mo or 2,460,37l 2/1949 Szwargulski 417/369 6 Claims, 7 Drawing Figures PATENTEI] JUL 2 9 I975 SHEET PATENTED JULZQ 1975 SHEET PUMPING SYSTEM FIELD OF THE INVENTION The present invention relates to pumping systems and more particularly to a quiet, self-priming, high speed pump driven by a commutator motor.

BACKGROUND OF THE INVENTION The prior art is aware of pumping systems or assemblies consisting of a commutator motor and of a directly driven pump, the commutating motor being sur rounded approximately over its entire outer periphery by a coolingjacket loaded with the liquid to be pumped and at least in part formed of the double wall of the motor housing, the motor further being completely sealed from the cooling jacket and being provided at its center with a ventilator mounted on the shaft for the purpose of air circulation.

Such pumping systems offer the great advantage of the high angular speeds of the commutator motors, so that, as a rule, the pumps designed as self-priming may be made correspondingly compact. Even the weight of the commutator motors will be slight at high angular speeds with respect to their outputs. On the other hand, operation of such commutator motors in these pumping systems is limited to the availability of external air for cooling if their operation is to be feasible.

US. Pat. No. 2,410,973 describes a pumping system of the kind described above, which is used and is meant to be used as a ,submersible or diving pump, that is, under water. The housing of this device is in the shape of a traversing double cylinder jacket serving as cooling means with the cooling water flowing in at the pump end and out at the opposite end. The commutator is mounted in the region of the end opposite that of the pump. Two housing chambers are provided between the pump-side bearing end-cover and the pump, wherein are mounted three relatively long labyrinth seal arrangements. An air circulation device is provided at the center of the motor, two ventilators being mounted on the shaft, one in the region of the pumpside bearing end-cover and the other outside the opposite bearing end-cover. This known pumping system is extraordinarily large and heavy and difficult to maintain, and therefore poorly suited for such use as, for instance, in a portable garden pump, because those parts, such as, for instance, the commutator, developing much heat are not arranged optimally with respect to the cooling jacket and therefore provision must be made, among others, for two ventilators. Further, replacing the carbon brushes of the commutator requires taking apart much of the motor, so that maintenance becomes complicated.

SUMMARY OF THE INVENTION that the commutators carbon brushes are covered outwardly by means of lids fastened to the motor housing, and in that the ventilator is mounted in the region of that bearing end-cover which is opposite to the one near the pump.

Because the commutator is mounted in the vicinity of the pump-side bearing end-cover, the latter also being cooled, which means that the motor is additionally provided with a front-end cooling besides the peripheral one, and because the ventilator is mounted at the opposite end of the motor, heat transfer from the commutator will take place by the shortest path and to a cooling surface which is large with respect to the commutator's volume, namely the front-end of the motor, and furthermore to a location where the cooling water still remains at its lowest temperature so that particularly effective heat transfer occurs. These optimum heat transfer processes in turn allow especially compact motor design. Because the carbon brushes are externally accessible, they may be easily replaced.

A centrifugal disk for leakage water and an associated leakage water channel in the pump-side bearing end-cover will be advantageously provided between a pump-side seal and the associated bearing. This measure allows further meeting the solution of the problem of compactness and lightness of weight of the system because it makes the vast labyrinth seal arrangements unnecessary, so that both the length of the motor and its weight may be reduced.

It will be of further advantage that the cooling jacket is formed, at least in part, by a sleeve surrounding the motor housing and removably fastened to the free front end of the motor. This sleeve is tightly connected by its pump-side edge to the outer jacket of that part of the housing which is double-walled. This permits especially convenient cleaning of the cooling jacket if the latter should foul on account of pumping very dirty liquids, the sleeve forming the cooling jacket being very easy to remove. Easy cleaning further guarantees maintenance of sufficient cooling since dirt deposits in the cooling jacket lead to reductions in heat transfer. Further, in contrast to the conventionally cast motor housing, such a sleeve may be made of sheet metal or such plates, contributing to weight reduction.

As regards a pumping system with a centrifugal pump, where the impeller is directly mounted on the shaft of the motor, and is mounted in the motor-side of the pumps front side, the invention provides a further advantageous characteristic in the nature of an annular slit between impeller and motor-side front-end of the pump, acting as communication between the pump and the cooling jacket. This ensures sufficient circulation for adequate cooling as regards the pumped liquid in the cooling jacket. This effect is further reinforced by the eddy currents of the liquid in the cooling jacket, which are caused by the pump-side surface of the impeller. This factor also reduces possible fouling of the cooling jacket, because only small-sized dirt may pass through the annular slit.

The large advantages of the pumping system of the invention rest in its use and application as a portable, acoustically damped and insulated unit inside a soundproof cover sealed on all sides and provided with a carrying handle. This arrangement meets in the extreme the desirability of the least possible noise generation. Otherwise, a soundproof cover sealed on all sides would completely suppress cooling; therefore, it is precisely the cooling of the commutator motor of the invention which provides a great advantage. Further, the

extensive enclosing of the commutator motor by means of a cooling jacket also reduces the noise.

BRIEF DESCRIPTION OF THE DRAWINGS Further advantages and characteristics of the invention will be found in the description of a preferred embodiment and by means of the drawing. The latter shows:

FIG. 1, a commutator motor according to the invention, in top view, from the pump-side end;

FIG. 2, the motor of FIG. 1, in top view, from the opposite end;

FIG. 3, a longitudinal section through a pumping system of the invention and along line IllIII of FIG. 1;

FIG. 4, the connection box of the motor in longitudinal section;

FIG. 5, the connection box of FIG. 4, in top view, shown open;

FIG. 6, a pumping system of the invention. inside a soundproof cover shown in longitudinal section, and

FIG. 7, a soundproof cover as in FIG. 6 in top view.

DESCRIPTION OF A PREFERRED EMBODIMENT A pump 2 is flanged onto a commutator motor 1. The latter is provided with a housing 3 which is doublewalled in the region of the pump-side end. Stator-plate assembly 4 is mounted in housing 3, the backs 5 of the stator laminations tightly abutting the inner wall of motor housing 3 and thus providing a heat-transferring connection. An armature consisting of winding 6 and shaft 7 is rotatably mounted inside the stator-plate assembly 4. Shaft 7 is supported in two bearing endcovers 8, 9 by means of ball-bearings 10. Whereas the pump-side bearing end-cover 9 is rigidly connected to housing 3, the bearing end-cover 8 mounted at the other end is drawn by means of nuts 11 on spacer bolts 12 against housing 3, these nuts also serving to fasten the stator-plate assembly 4 in housing 3, a nut 12' on each spacer bolt being drawn against the stator-plate assembly 4. The outer races of ball bearings are maintained in place by O-rings 13 of elastic material and strongly compressed in the normal state, which are inserted in the ballbearing boreholes of bearing endcovers 8, 9, so that even if there were expansion of the ballbearing boreholes, for instance from temperature rises, these outer races would not be dragged along by shaft 7.

A radial ventilator 14 is mounted on shaft 7 between armature winding 6 and bearing end-cover 8. By means of compression springs 15' pressing against the stator plates assembly 4 and guided by the spacer bolts, an air deflection plate 15 is kept in place, forcing the air in motor housing 3 to flow through the passage chambers upon rotation of shaft 7 and hence of the radial ventilator 14, i.e., from the latters compression side 16 externally past the air deflection plates 15 and into said passage chambers, which are formed from the flattened stator lamination backs 17 and the inner housing wall 18. Following its reversal at the other pump-side end of housing 3, the air will flow through the clear passage chambers bounded by the stator lamination inner sides 19 and the armature winding 6, back to the suction side 20 of the radial ventilator 14. The arrows 21 indicate the direction and course of the flow.

A commutator 22 and a balancing disk 23 are mounted on shaft 7 between the pump-side bearing end-cover 9 and armature winding 6.

Carbon brushes 27 rest movably against a contact plate 26 under pressure from a compression spring 25, while pressing with their other ends against commutator 22 and being housed in a carbon brush holder 24 fastened to housing 3. Compression spring 25 and contact plates 26 serve to connect electrically comrnu tator 22 with stator winding 28. Carbon brushes 27 are outwardly protected by means of covers 29 which are screwed by bolts 30 to housing 3 and thereby shielded against water jets.

A slip ring seal 31 is mounted outside of ballbearing 10 in bearing end-cover 9, which on one hand is sealed with respect to the bearing end-cover 9 by means of an O-ring 32 and on the other with respect to shaft 7 by means of O-ring 33. Any liquid still penetrating through the slip-ring seal will be collected by a centrifugal disk 34 mounted on shaft 7 between slip-ring seal 31 and ball-bearing 10 and cast against the walls of an annular space 35, whence it will be drained through the leakage water channel 36 to the outside; therefore, penetration of the liquid into the center of motor housing 3 is impossible.

The bearing borehole of bearing end-cover 8 is completely sealed by means of a stopper 37, which may be screwed into the aperture of the bearing end-cover. Complete sealing between the outer periphery of bearing end-cover 8 and housing 3 is achieved by means of an O-ring seal 38.

A space 39 above ballbearing 10 in bearing endcover 9 is made of one piece with the latter and with motor housing 3 in the form of connection box housing the ON and OFF switch 40 for the motor and a spark interference filter 42 elastically held by a spring member 41 between switch and inner wall of space 39. The latter is sealed watertight upwards by a cover 43 itself fastened to housing 3 by means of screws 44'. Cover 43 is made of plastic and provided above the switch with a thin, sprayed-on membrane 44, so that the switch 40 may be actuated externally by deforming this membrane. As shown in FIG. 5, a terminal board 45 is located next to switch 40, which is hooked up to the power cable 46 held in a traction relief clamp 47. Cable 46 is sealed by a grommet 48 and passes out of space 39.

As already mentioned, housing 3 in the region of bearing end-cover 9 is made double-walled beyond commutator 22 by providing a cylindrical outer jacket 49 of one piece with housing 3, the latter being approximately coaxially surrounded by the spaced jacket. The latter also rests on fins 50 extending longitudinally on housing 3 and cast upon it. These fins extend beyond the outer jacket 49 almost to the end of housing 3. An approximately cylindrical sleeve is slipped on the free end of outer jacket 49, inserting an O-ring seal providing tightness, which is further sealed at its other end opposite bearing end-cover 8 by an O-ring seal 53. This sleeve is screwed onto bearing end-cover 8 by means of bolts 54. The latter are tightened each by means of a lock ring 56 against axial displacements inside shoulders of the edge of sleeve 52, so that when screwing bolts 54 into bearing end-cover 8, sleeve 52 will be pulled on the outer jacket 49, or, when unscrewing bolts 54 from bearing end-cover 8, will be pulled down by the latter. Thus, the axial fastening of bolts 54 serves to facilitate assembly and disassembly of sleeve 52.

A space, serving as a cooling jacket, is defined by outer jacket 49 and sleeve 52, which is approximately cylindrical and surrounds the motor housing. said space being only interrupted in the region of the pump-side bearing end-cover9 by chamber 39 and by the commu tator brushes mounted in the horizontal plane and the longitudinal fins 50. Because of the premature ending of fins 50, these interruptions form longitudinal channels 57 interconnected by a continuous channel 58 of circular shape at their ends facing bearing end-cover 8'.

As regards the pump-side end, the outer jacket 49 extends beyond bearing end-cover 9 and is provided with a flange 59 at its end which may be bolted by means of boreholes 60 to the corresponding flange 61 of housing 62 of pump 2, inserting an O-ring seal 63. Simultaneously, a motor-side connecting part 64 of pump 2 is clamped between flange 61 and outer jacket 49. An impeller 65 of pump 2, which is designed as a self-priming centrifugal pump, is mounted on the free end of shaft 7 projecting beyond bearing end-cover 9, pumping buckets 67 projecting freely and approximately radially mounted on hub 66 which is flush with connecting part The liquid to be pumped will be sucked in through an inlet connection not shown here in the direction of flow arrow 68 and via a suction chamber 69, and in central manner by means of impeller 67, then it will be flung out approximately in radial direction and conveyed by means of the helically mounted deflection plate 70 into compression chamber 71, which it will leave via outlet connection 72.

The compression side of impeller 65 communicates with chamber 74, which is bounded by bearing endcover 9, outer jacket 49 and connecting part 64, via an annular slit 73 between hub 66 of impeller 65 and connecting part 64, so that a constant liquid exchange is guaranteed between cooling jacket 74, 57 and 58 surrounding the entire motor housing 3 and pump 2, as was surprisingly found. even though there is no direct connection between these cooling chambers and the suction side of the pump. This liquid exchange is maintained due to the fact that a constant pressure is not created along the circumference of the pump wheel, resulting in the creation of a pressure gradient which in turn produces a circulatory flow in the cooling jacket.

Cooling of motor 1 occurs as follows: After starting the motor, the pumping liquid fills chamber 74, channels 57 and annular space 58, there occurring a constant change of water with simultaneous heat transfer through annular slit 73. The heat generated in stator winding 28 in part is removed from the backs 5 of the stator laminations and from the housing inner wall at the contact area between them to the liquid, and to a further extent is absorbed by the air circulated by ventilator 14 and released by latter to the inside surface of the bearing end-cover 9 or to that of motor housing 3, and from there is transferred to the liquid.

The heat generated by armature winding 6 and by commutator 22 represents an appreciable part of the entire heat being generated by the motor and will be transferred in part by the circulating air in the manner already described to the cooling liquid and in part directly via shaft 7 into chamber 74 to the cooling liquid.

FIGS. 6 and 7 shows the application of a commutatormotor and pump system 1, 2 in the form of a portable, soundproof unit. Motor 1 and pump 2 are mounted on a base plate 82 by means of soundinsulating elements, especially commercial vibration mounts 81 and fastened to it by such suitable means as bolts 83. The motor-pump system 1, 2 is surrounded at slight spacing with a soundproofing cover 84; however, there is no direct contact between system and cover 84. Merely inlet connector 85 and outlet connector 72 of pump 2lead out of soundproofing cover 84 at the top. Power. connection 46 to motor 1 passes through a small aperture at the lower edge of the soundproofing cover and is fastened to base plate 82 by means of a traction relief clamp 86. y

A carrying handle 87 is fastened by means of screws 88 to the box-like soundproof cover 84 which is roughly shaped to fit the motor-pump system 1, 2. An aperture '89 is located in the soundproof cover 84 underneath the carrying handle 87 and above the ON and OFF switch 40 of motor 1, whichis sealed by means of membrane 90 that is welded on or sprayed on so as to allow activating the switch 40 through that membrane. The soundproof cover 84 is mounted by means of screws 91 to motor 1, but may also be directly connected to base plate 82 in suitable manner.

A peripheral seal 92 is appropriately provided between the peripheral lower edge of soundproof cover 84 and base plate 82, in order to achieve sufficient sealing against humidity and also to prevent the occurrence of an acoustic path between the inner chamber and the surroundings.

The soundproof cover 84, base plate 82 and carrying handle 87 and if necessary also the inlet and outlet connectors 85, 72 will be appropriately made of a sufficiently impact-proof plastic, which with respect to metal in general will offer the advantage of lesser sound conductivity. It will furthermore be suitable to provide the inside of the soundproof cover with a layer of sound attenuating material, which may be glued on or sprayed on. This also applies to the base plate 82. Sealed-pore foams are especially suitable for additional coatings of soundproofing materials, since on one hand they will be extremely light-weight and on the other provide high attenuation properties.

It will be obvious to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown in the drawings and described in the specification.

What is claimed is:

1. In a pumping system comprising a commutator motor having a housing, a shaft, a commutator, carbon brushes and bearing end-covers at the pump side and the opposite side thereof, a pump directly driven by said motor, a cooling jacket formed at least in part by a double-walled design of said motor housing surrounding substantially the entire periphery of said motor, filling means for filling said cooling jacket with the liquid to be pumped when in use, said motor being completely sealed from said cooling jacket, and ventilator means including a ventilator mounted on said shaft for forcing air circulation at the center of said motor, the improvements wherein:

said pump-side bearing end-cover is surrounded by said cooling jacket;

said commutator is mounted in the region of said pump-side bearing end-cover;

said motor housing has covers therein for outwardly shielding the carbon brushes of said commutator; and

7 said ventilator is mounted in the region within the bearing end cover which is opposite to that at the pump-side.

2. A pumping system in accordance with claim 1 wherein said motor includes a pump-side bearing for rotatably supporting said shaft and a pump-side sealing means for substantially preventing liquid from entering said pump-side bearing end-cover. and further including a centrifugal disk mounted coaxially on said shaft and said pump-side bearing end-cover has a leakage water channel associated with said disk, said disk and said channel being provided between said pump-side sealing means and said pump-side bearing.

3. A pumping system in accordance with claim 1 wherein said cooling jacket consists in part of a sleeve surrounding said motor housing and removably mounted on the side of said motor opposite said pump.

4. A pumping system in accordance with claim 3 wherein said sleeve is tightly connected at the pumpside edge thereof with the outer jacket of the doublewalled part of said motor housing.

5. A pumping system in accordance with claim 1 wherein said filling means includes an impeller directly mounted on said shaft at the motor-side of said pump and further including an annular slit means in the motor-side of said pump for serving as communication between said impeller and said cooling jacket.

6. A pumping system in accordance with claim 1 fur ther including an omnidirectionally scaled soundproof cover and a handle connected thereto. said cover surrounding said motor and said pump. 

1. In a pumping system comprising a commutator motor having a housing, a shaft, a commutator, carbon brushes and bearing endcovers at the pump side and the opposite side thereof, a pump directly driven by said motor, a cooling jacket formed at least in part by a double-walled design of said motor housing surrounding substantially the entire periphery of said motor, filling means for filling said cooling jacket with the liquid to be pumped when in use, said motor being completely sealed from said cooling jacket, and ventilator means including a ventilator mounted on said shaft for forcing air circulation at the center of said motor, the improvements wherein: said pump-side bearing end-cover is surrounded by said cooling jacket; said commutator is mounted in the region of said pump-side bearing end-cover; said motor housing has covers therein for outwardly shielding the carbon brushes of said commutator; and said ventilator is mounted in the region within the bearing end cover which is opposite to that at the pump-side.
 2. A pumping system in accordance with claim 1 wherein said motor includes a pump-side bearing for rotatably supporting said shaft and a pump-side sealing means for substantially preventing liquid from entering said pump-side bearing end-cover, and further including a centrifugal disk mounted coaxially on said shaft and said pump-side bearing end-cover has a leakage water channel associated with said disk, said disk and said channel being provided between said pump-side sealing means and said pump-side bearing.
 3. A pumping system in accordance with claim 1 wherein said cooling jacket consists in part of a sleeve surrounding said motor housing and removably mounted on the side of said motor opposite said pump.
 4. A pumping system in accordance with claim 3 wherein said sleeve is tightly connected at the pump-side edge thereof with the outer jacket of the double-walled part of said motor housing.
 5. A pumping system in accordance with claim 1 wherein said filling means includes an impeller directly mounted on said shaft at the motor-side of said pump and further including an annular slit means in the motor-side of said pump for serving as communication between said impeller and said cooling jacket.
 6. A pumping system in accordance with claim 1 further including an omnidirectionally sealed soundproof cover and a handle connected thereto, said cover surrounding said motor and said pump. 